Yes...but would a fuse big enough to start, blow after the engine starts and the starter just keeps spinning? What is the amperage increase if any ?

Like Ski said...not uncommon...but fires are rare and what amperage do you fuse for?

I have had 3 stuck starter incidents with hot starters but no fires. One took hours to find.

That spinning starter motor would have eventually seized. Where would the current go then or how about a solenoid locking up until it glows. I have seen the results and now have fuse on all my batteries.

__________________

Advertisement

__________________
If you can live with the consequences, go for it - wg
Y'am what I y'am an' thats' all that y'am - Popeye
As God is my witness, I thought turkey's could fly. Mr.C

That spinning starter motor would have eventually seized. Where would the current go then or how about a solenoid locking up until it glows. I have seen the results and now have fuse on all my batteries.

True the locked rotor amperage would be way higher...but I think most wiring is bigenough...now you have my curiosity up...yes ...yes... I do have it fused...but I understand the no fuse concept.

Still though...with so few fires despite runaway starters...I wonder why unless the ampacity of the wire is usually close enough.

800 to 1000amps going to a starter is way too much for me. (seize, melt, short, starter or solenoid) I feel safer with a fuse given the stuff that I have investigated. A fuse on all my positive terminals is real cheap protection.

__________________
If you can live with the consequences, go for it - wg
Y'am what I y'am an' thats' all that y'am - Popeye
As God is my witness, I thought turkey's could fly. Mr.C

Man that is a bit of a scare! Good info, thanks for sharing. Glad you were in a Lock and tied up when you discovered it.

We just installed 3 water alarms forward, engine room and stern lazarette. We're thinking about installing smoke alarms and a camera in the engine room as we don't have them. If anyone has any specific suggestions on them feel free to pass along.

Both Kidde and First Alert have wireless battery powered smoke detectors. I put one in engine room, one in pilot house and one in cabinet on flybridge. If engine room unit is tested or activated, both the others also activate. I cannot stress enough the importance of hearing alarm on fly bridge. My best friend lost his Westport 52 (and nearly his life) because he was on fly bridge and couldn't hear alarm in pilot house.

ABYC requires fuse protection on the positive conductor of any battery but for batteries for starting engines. I think they dropped the ball on this one. This is a very good case for fuses on all positive battery conductors.

I think they figured it out before writing the standards. The current draw of the starter is close enough to the capacity of the cable (and the capacity of the battery) that circuit protection that would allow for normal operation would be ineffective.

I had a starter do this on a Westerbeke diesel in my ex Navy Whaleboat. Heard the whine after starting, shut down the engine and the whining kept going. Put my hand on the starter and felt the hum. Rapped it lightly with a hammer, and it quit. Never done it again.

I had a starter do this on a Westerbeke diesel in my ex Navy Whaleboat. Heard the whine after starting, shut down the engine and the whining kept going. Put my hand on the starter and felt the hum. Rapped it lightly with a hammer, and it quit. Never done it again.

So how common is it for a boat's starter to turn on without human intervention and keep running?

This doesn't happen on it's own. When the OP started the engine this started.
It's a direct result of human pressing the starter button/ turning a key during the start cycle. Either the starter button fails by sticking ON, and keeps sending power to starter, or the solenoid has a closed short that keeps it engaged, or the bendix fails and sticks out and spins the starter to death. I have seen key starts on diesels that fail (fairly often) enough to warrant a push button start. Most professional installations have push button for this reason.

I had to tow a yanmar SF in years ago that had an exploded starter. The owner was lamenting they couldn't figure out what the 'new' noise was. Until it got really silent. The he got a tow home! The starter was blown off the bell housing by the force of it locking up after it melted the innards.

I had to tow a yanmar SF in years ago that had an exploded starter. The owner was lamenting they couldn't figure out what the 'new' noise was. Until it got really silent. The he got a tow home! The starter was blown off the bell housing by the force of it locking up after it melted the innards.

Now THAT would be downright scary. Fortunately my wife smelled something hot and that's when this whole thing started.

We probably will never know which came first, the chicken or the egg. In other words, did the starter run away and cause the other issues or did something else start the chain of events and cause the starter to runaway.

We can speculate till the cows come home but we probably never will know for certain.

By way of an update. We're now just waiting for a new helm panel to be built. Once that is done the trim tab gauges and a new digital Systems Monitor panel will be installed in it and we'll be finished. Well, except for the sea trial to make sure everything is working properly.